On Tue, Sep 18, 2018 at 8:28 PM Jinhua Luo <luajit...@gmail.com> wrote:
> > https://www.postgresql.org/docs/current/static/postgres-fdw.html#id-1.11.7.43.12 > > As the doc said, the REPEATABLE READ isolation level is used to get > snapshot-consistent results. > > But is it possible that postgres_fdw could get to know which remote > queries involved by each top outer command in the local transaction, > and use the same snapshot in the remote server to execute them > sequentially? For example, could we use PREPARE TRANSACTION and SET > TRANSACTION SNAPSHOT to archive this goal? Then we could use READ > COMMITTED on both sides? > > I guess the problem is 1. exporting snapshots is not cheap 2. tracking prepared transactions is not implemented. See a nearby thread on "transaction involving multiple foreign server". -- Best Wishes, Ashutosh Bapat
